Crushers are used to crush large particles (e.g., rocks) into smaller particles. One particular type of crusher is known as a cone crusher. A typical cone crusher includes a frame supporting a crusher head and a mantle secured to the head. A bowl and bowl liner are supported by the frame so that an annular space is formed between the bowl liner and the mantle. In operation, large particles are fed into the annular space between the bowl liner and the mantle. The head, and the mantle mounted on the head, gyrate about an axis, causing the annular space to vary. As the distance between the mantle and the bowl liner varies, the large particles are impacted and compressed between the mantle and the bowl liner. The particles are crushed and reduced to the desired product size, and then dropped down from between the mantle and the bowl liner.
U.S. Pat. No. 4,750,681, which issued to Sawant et al. on Jun. 14, 1988, discloses such a cone crusher. The crusher includes a head 146 which is supported on a cylindrical support shaft 30. Eccentric 48 is rotatable about the shaft 30 and is attached to the head 146. The shape of the counterweight 55 is designed to compensate for the mass eccentricity of the eccentric 48 and head assembly 144 so that the assembly of eccentric 48, counterweight 55 and head assembly 144 is balanced to produce no net horizontal forces on the foundation when the mantle 150 is half worn.